Variable vane agitator with self-compensating means



March 31, 1970 A. MASON ET AL 3,503,086

VARIABLE VANE AGITATOR WITH SELF-COMPENSATING MEANS 3 Sheets-Sheet 1 Filed June 5, 1968 IN VENTORS' March 1970 A. MASON ET AL 3,503,086

VARIABLE VANE AGITA'IOR WITH SELF-COMPENSATING MEANS Filed June 5, 1968 3 Sheets-Sheet 2 l N VENTORS .44 TA/O/VY M1 5 av 1(6/774 D. SAL/$60K) 0,4 m; A. M4725 TTORNEYS March 31, 1970 A. MASON ET AL 3,503,086

VARIABLE VANE AGITA'I'OR WITH SELF-COMPENSATING MEANS Filed June 5, 1968 3 Sheets-Sheet 5 INVENTOR5 fl/vn/o/vy Asa/v DAV/ID MATZEN v ATTORNEYS United States Patent O US. Cl. 8-159 18 Claims ABSTRACT OF THE DISCLOSURE A washing machine including an agitator assembly for agitating the material to be laundered. The agitator assembly includes a rotatable agitator shell and a plurality of agitation vanes rotatable with the shell and adjustable for varying the level of agitation in accordance with the quantity of material being laundered. The agitator shell is driven by an oscillating rotatable drive shaft to which it is connected by means of a coupling arrangement including a spring member so that the agitator shell lags behind or follows the drive shaft by an angle which is proportionate to the turn-resisting force imposed on the agitator shell and the agitation vanes by the laundry ma terial. The agitation vanes are automatically moved to a position of adjustment as a function of the angle by which the agitator shell lags behind the drive shaft.

BACKGROUND OF THE INVENTION This invention relates generally to the field of washing machines and more particularly to washing machines of the agitator type.

Agitator type Washing machines generally employ an agitator shell which oscillates rotatably on a vertical axis. One or more agitation vanes extend radially from the agi tator shell to increase the agitation of the laundry liquid and the laundered material.

It is usually desirable to vary the level of agitation as the quantity of laundered material varies. For example, a low level of agitation is generally preferred when the quantity of laundered material is low whereas a high agitation level is preferred as the quantity of laundered material increases.

Agitator type washing machines having adjustable agitation vanes to vary the level of agitation are known in the prior art. Such arrangements require manual adjustment of the vanes, however, which is not only time consuming and effort expending but often results in an improper adjustment of the vanes due to a miscalculation on the part of the operator with respect to the quantity of laundry material loaded in the machine.

SUMMARY OF THE INVENTION The present invention overcomes the disadvantages of the prior art by providing a method of and apparatus for automatically adjusting the agitation level of the washing machine to correspond with the quantity of laundry material in the machine. Manual adjustment is not required an deven if the quantity of laundry material is changed in the course of a wash cycle the level of agitation of the machine will be automatically readjusted to correspond to the adjusted load.

The method of the present invention may be briefly summarized as comprising the steps of transmitting a driving torque to the agitator shell of the agitator as sembly, subjecting the agitator shell and an adjustable agitation vane connected thereto to a turn-resisting force which is imposed by the washing load in the machine,

"ice

increasing the driving torque to a level which exceeds the turn-resisting force in order to commence rotation of the agitator shell and adjusting the agitation vane in relation to the level of the driving torque required to exceed the load-imposed turn resisting force.

The invention may also be summarized as comprising means for carrying out the aforementioned method and includes radially or axially adjustable agitation vanes which are moved between low and high agitation positions as a function of the magnitude of the turn-resisting forces imposed on the agitator assembly by the load of laundry material. Thus as the quantity of laundry material in the washing. machine increases, the force acting on the agitator assembly to resist the driving force increases, and as the increase occurs the agitation vanes are automatically adjusted to a higher agitation level position commensurate with the increased load. The re verse situation occurs when the amount of laundry material in the machine is reduced.

The agitator assembly oscillates about an axis of rotation. The two positions during each cycle of oscillation at which the velocity of the agitator assembly is re duced to zero in changing direction of rotation may be considered the limiting end positions of the agitator assembly. At such positions the turn resisting force acting on the agitator assembly is sharply reduced.

In one embodiment of the invention the load-resisting force acting on the agitator assembly in both directions of rotation serves to move the agitation vanes to their adjusted positions. Thus at the limiting end positions of the agitator assembly the agitation vanes move to a low level agitation position but then immediately readjust to correspond with the load in the machine when the agitator assembly has moved from the limiting end position.

In another embodiment of the invention the turn-resisting force caused by the washing load serves to adjust the position of the agitation vanes only in one direction of rotation. As the agitator assembly rotates in an opposite direction of rotation the agitation vanes are maintained at the position to which they were moved in the first direction of rotation.

As a consequence of the invention the washing machine operator is not required to make a mental calculation of the load and furthermore is not required to manually adjust the agitation vanes once he has arrived at What he considers to be the proper adjustment. Accordingly, the present invention not only reduces the time and effort required in operating the washing machine but also provides optimum results by eliminating the guess work formerly required in estimating the quantity of the wash load.

It is, therefore, an object of the present invention to provide, in an agitator-type washing machine, a method of and means for automatically adjusting the agitation level of the machine to correspond to the quantity of laundry material being washed.

Another object of the invention is to reduce the time and effort required in adjusting the agitation vanes.

Another object is to improve washing results by eliminating the need for operator adjustment-selection with respect to the agitation vanes.

A further object of the invention is to provide automatic adjustability in a simplified fashion without materially increasing costs or potential maintenance problems.

Many other features, advantages and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheets of drawings, in which preferred structural embodiments incorporating the principles of the invention are shown by way of illustrative example only.

3 BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevational view of an agitator type washing machine constructed in accordance with the principles of the present invention with portions thereof broken away and other portions shown in section to reveal the relative positioning of parts.

FIGURE 2 is an enlarged fragmentary vertical elevational view of the agitator assembly shown in FIGURE 1.

FIGURE 3 is a horizontal sectional view taken along lines III-III of FIGURE 2.

FIGURE 4 is a fragmentary View similar to FIGURE 3 but illustrating a different vane adjustment arrangement.

FIGURE 5 is similar to FIGURE 2 but illustrates another embodiment of an agitator assembly constructed in accordance with the principles of the present invention.

FIGURE 6 is a horizontal sectional view taken along line VI--VI of FIGURE 5 with the cap of the agitator assembly and other parts removed.

FIGURES 7 and 8 are similar to FIGURE 6 but show the various parts of the agitator assembly in different relative positions.

FIGURE 9 is a fragmentary vertical view taken along lines IX-IX of FIGURE 5, illustrating a vertical slot formed in an inner agitator shell of the agitator assembly and a pin extending from an outer agitator shell through the slot.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGURE 1, an agitator type washing machine constructed in accordance with the principles of the present invention is indicated generally at reference numeral 10. Various components of the Washing machine 10 include an outer cabinet 11 at the top of which is mounted a hinged cover 12, an imperforate tub 13 for receiving a supply of laundry liquid, a perforate drum 14 for receiving the material to be laundered, registered openings 16 and 17 through which laundry material is loaded into the drum 14, an agitator assembly 18 which oscillates rotatably on a vertical axis for providing the agitation to the laundry liquid and the laundered material and a drive shaft 19 which drives the agitator assembly 18. The drive shaft 19 is connected to a suitable driving mechanism such as an electric motor mounted in the lower portion of the cabinet 11 whereby the drive shaft oscillates back and forth during a wash cycle and spins at high speed in one direction in the usual manner during a spin cycle. Bottom walls 20 and 21 of the tub 13 and the drum 14 slope upwardly at the central portions thereof and are provided respectively with openings 22 and 23 through which the drive shaft 19 projects up into the agitator assembly 18.

In the embodiment of the agitator assembly 18 illustrated in FIGURES 1-4, the level of agitation is regulated by the adjustment of a plurality of radially movable vertically upstanding thin, disc-shaped agitation vanes, only one of which is illustrated in the drawings at reference numeral 24. As the vane 24 is moved radially outwardly from the axis of rotation or oscillation of the agitator assembly 18, the level of agitation increases. Conversely, when the agitation vane 24 is moved radially inwardly the level of agitation decreases.

Referring to FIGURES 2-4, the agitator assembly 18 may be further'characterized as comprising inner and outer agitator shells 26 and 27, both of which are tubularly shaped and axially aligned with the axis of the drive shaft 19. The upper end of the inner agitator shell 26 comprises a centrally bored tubular portion 28 which is internally splined at 29 to receive a complementarily splined upper end 30 of the drive shaft 19. The inner agitator shell 26 is, therefore, connected to the drive shaft 19 for joint oscillation and rotation.

An outer surface 31 of the upper end portion 28 as well as a radial shoulder 32 of the inner agitator shell 26 are smooth, the radial shoulder 32 supporting a companion shoulder 33 formed on the outer agitator shell 27, and the smooth outer surface 31 of the upper end section 28 providing a bearing surface for a reduced diameter end portion 34 of the outer agitator shells 27. The inner and outer agitator shells 26 and 27 are, therefore, arranged and mounted for relative rotation with the radial shoulder 33 and the cylindrical surface 31 providing the bearing surfaces between the two shells. A cap 36 is mounted on the upper end of the drive shaft 19 and overlies the end portions of the inner and outer agitator shell 26 and 27.

The agitation vane 24 is diposed within a vane guide 37 which comprises a top wall 38 and a pair of spaced parallel vertical side walls 39 and 40. The vane guide 37 is formed on and projects radially outwardly of a body portion 41 of the outer agitator shell 27 and a distal end 42 thereof is open so that the vane 24 is movable within the confines of theside walls 39 and 40 from a radially inner or low level agitation position shown in the solid lines in FIGURE 2 to a radially outer or high level agitation position as shown in the dashed lines of FIGURE 2.

The illustrated embodiment of the agitation vane 24 comprises spaced parallel top and bottom walls 43 and 44 and spaced parallel end walls 46 and 47. The bottom wall 44 is supported in sliding engagement on a top wall 48 of a skirt 49 extending radially outwardly and sloping axially downwardly from the bottom end of the inner agitator shell 26. A pin or cam follower member 50 projects downwardly from the bottom wall 44 and is received in a curved slot 51 formed in the skirt 49, the side walls of the slot 51 providing cam surfaces for the pin 50.

In the embodiment shown in FIGURE 3, three agitation vanes 24 and vane guides 37 are spaced equally about the circumference of the outer agitator shell 27. The slots 51 each extend from an inner end 52 to an outer end 53 disposed not only in circumferentially spaced but also in radially outwardly spaced relation to the inner end 52. It will be apparent from FIGURE 3 that as the inner and outer agitator shells 26 and 27 are rotated with respect to one another the agitation vanes 24 rotate with the outer agitator shell 27 and also move radially outwardly to a high level agitation position as shown in the dashed lines at reference numeral 24.

As shown in FIGURE 2 an outer cylindrical wall 54 of the inner agitator shell 26 is radially spaced from an inner cylindrical wall 56 of the outer agitator shell 27 and in the chamber 57 formed therebetween is disposed in a helical coil spring 58, one end of which as shown at 59 protrudes through an aperture 60 formed in the outer agitator shell 27, and an opposite end 61 of which protrudes through an aperture 62 formed in the inner agitator shell 26.

In operation the inner agitator shell 26 is directly coupled to and is driven jointly with the drive shaft 19. The inner agitator shell 26 in turn drives the outer agitator shell 27 through the helical spring 58.

As the drive shaft 19 begins turning in one direction of rotation the inner agitator shell 26, of course, turns with it. However the load of laundry material within the drum 14 imposes a counterforce or turn-resisting force on the outer agitator shell 27 proportionate to the quantity of laundry material in the drum 14.

, Since the outer agitator shell 27 is subjected to a torque acting against the torque being applied by the inner agitator shell 26 through the spring 58, the outer agitator shell 27 does not immediately rotate jointly with the inner agitation shell 26 but instead lags behind the inner agitator shell 26, thus producing a winding force on the spring 58. This winding force increases until the torsional force applied by the spring 58 to the outer agitator shell 27 exceeds the turn-resisting force to which the outer agitator shell 27 is subjected by virtue of the washing load in the drum 14.

As the inner and outer agitator shells 26 and 27 rotate relative to one another as the spring 58 is winding up, the agitation vanes 24 are moved radially outwardly a distance which corresponds to the angle of relative rotation between the inner and outer agitator shells 26 and 27 which angle, in turn, depends upon the magnitude of the turn-resisting force being applied to the outer agitator shell 27 by the laundry material. Thus as the size of the load of laundry material within the drum 14 is increased the angle of displacement or relative rotation between the inner and outer agitator shells 26 and 27 increases proportionately. As a consequence the level of agitation, which varies as a function of the position of the agitation vanes 24, corresponds proportionately to the size of the load of laundry material in the drum 14.

As the drive shaft 19 oscillates through each oscillation cycle and approaches a limiting end position of oscillation or a position at which the direction of rotation is reversed, the turn-resisting force acting on the outer agitator shell 27 is substantially reduced and the tendency of the spring 58 is to cause the outer agitator shell 27 to rotate relative to the inner agitator shell 26 to bring the two shells back from a relatively rotationally displaced position to the relatively neutral position which they assumed initially while at rest. At that point in time the agitation vanes 24 are moved radially inwardly to the low level agitation position thereof.

In the embodiment shown in FIGURE 3 the agitation vanes 24 are moved to the high level agitation position thereof only as the drive shaft 19 rotates in one direction of rotation, since the vanes assume a radially inward position as the drive shaft completes the oscillation cycle in an opposite direction of rotation. In the embodiment shown in FIGURE 4, however, each of the slots 51a formed in the skirt 49 extends from a radially inner point 52a in opposite directions to circumferentially and radially outwardly spaced points 53a. In this embodiment, therefore, the agitation vanes 24 are moved to a higher level agitation position as the drive shaft 19 rotates in both directions of rotation. The vanes 24 assume a low level agitation position only momentarily at the limiting end positions of rotation of the drive shaft 19.

In the embodiment shown in FIGURES 24, the agitation vanes 24 constitute vanes extensions of the vane guides 37, since the guides themselves perform an agitation function. In the embodiment shown in FIGURES 5-9 the agitation vanes are adjusted in a different manner but perform a similar agitation function.

Referring to FIGURES 5-9, wherein parts corresponding to similar parts shown in FIGURES 2-4 are indicated by like reference numerals increased by 100, a series of relatively thin vertically upstanding circumferentially spaced vane guides, one of which is indicated at reference numeral 137, project upwardly from the skirt 149 of the inner agitator shell 126. A corresponding number of adjustable agitation vanes 124 are formed on the outer agitator shell 127 and comprise a top wall 143, an outer end wall 146 and a pair of spaced parallel vertically upstanding walls 146a. A bottom end 144 of the agitation vane 124 is open to receive the vane guide 137.

In the embodiment shown in FIGURES 5-9, the outer agitator shell 127 is movable relative to the inner agitator shell 125 in an axial direction. The agitation vanes 124 serve as vane extensions of the vane guides 137 to increase the level of agitation as the outer agitator shell 127 moves axially upwardly relative to the inner agitator shell 126. The high level agitation position assumed by the agitation vanes 124 is a raised position of the outer agitator shell 127 is indicated in the dashed lines at reference numeral 124a.

As shown in FIGURE 5, a cylindrically shaped cam block 163 is mounted on the splined end 130 of the drive shaft 119 for joint rotation therewith. A smooth cylindrical outer wall 164 of the cam block 163 is disposed in proximately spaced relation to a complementarily shaped smooth inner surface 166 of a reduced diameter upper end portion 167 of the inner agitator shell 126. An annularly shaped radially inwardly extending shoulder 168 is formed on the inner surface 166 and extends under a bottom wall 169 of the cam block 163 to prevent axial movement of the inner agitator shell 126 while enabling the inner agitator shell to rotate relative to the cam block 163.

The outer agitator shell 127 also comprises a reduced diameter upper end portion indicated at reference numeral 170, which portion comprises a smooth cylindrical inner wall 171 disposed in proximately spaced relation to an outer wall 172 of the inner agitator shell 126. A plurality of circumferentially spaced pins or cam follower members as indicated at reference numeral 173 are connected in fixed assembly to the outer agitator shell 127 and project radially inwardly through complementarily arranged elongated vertical slots 174 formed in the inner agitator shell 126. The pins 173 each extend into a corresponding one of a plurality of cam slots 176 formed in the outer cylindrical surface 164 of the cam block 163. Each of the cam slots 176 extends in a helical fashion circumferentially from a lower end 177 to an axially upwardly spaced end 178, side walls 179 and 180 serving as cam surfaces for the cam follower members or pins 173.

The cam block 163 further comprises a reduced diameter cylindrical wall 181 about which is wrapped a oneway spring clutch 182. An upper end 183 of the spring clutch extends radially inwardly over a top wall 184 of the cam block 163 whereas a bottom end 186 projects through an aperture 187 formed in the reduced diameter portion 167 of the inner agitator shell 126.

An agitator assembly cap 188 covers the upper end of the assembly 118 and is mounted on the drive shaft 119 by means of a suitable fastening device such as a threaded screw 189. Housed within the cam 188 is a helical spring 190 which is disposed in surrounding relation adjacent the reduced diameter upper portion 167 of the inner agitator shell 126. An upper end 191 of the spring 190 bottoms on the underside of the cap 188 and the lower end 192 thereof bottoms on a top wall 193 of the outer agitator shell 127.

FIGURE 5 illustrates the relative disposition of parts when the drive shaft 119 is at rest. The spring 190 has biased the outer agitator shell 127 axially downwardly such that the agitation vanes 127 provide no substantial vane extension of the vane guides 137 During operation, when the drive shaft 119 and the cam block 163 begin to rotate in a counterclockwise direction as indicated by the arrow 194 in FIGURE 6, the outer shell 127 is subjected to a load-resisting force. Since the pins 173 extend through the vertical slots 174 formed in the inner agitator shell 126, the load-resisting force is also transmitted to the inner agitator shell 126.

Consequently the cam block 163 will begin to turn relative to the inner and outer agitator shells 126 and 127, causing the pins or cam follower members 173 to move Within the cam slots 176, the effect of which is to move the outer agitator shell 127 axially upwardly. As this upward movement of the outer agitator shell 127 occurs, the helical spring 190 is compressed, thereby increasing the biasing eifect thereof on the outer agitator shell 127 in a downward direction. The pins 173 will continue to turn and rise in the cam slots 176 until the biasing force of the spring 190 increases to a level of balance with the load-resisting force acting on the outer agitator shell 127. As the outer agitator shell 127 moves increasingly upwardly the agitation vanes 124 provide increased extensions of the vane guides 137, thus increasing the effect action surfaces of the agitation vanes and increasing the level of agitation proportionately.

After the outer agitator shell 127 has moved upwardly sufi'iciently to increase the biasing force of the spring 190 to balance the loadaesisting force acting on the agitator shell 127, the outer agitator shell and hence the inner agitator Shell 126, which is co-rotatably coupled to the outer agitator shell 127, will rotate jointly with the cam 7 block 163 and the drive shaft 119 until the drive shaft 119 reaches its limiting end position in a counter-clockwise direction of rotation.

As the drive shaft 119 rotates in a counter-clockwise direction the one-way spring clutch 182 does not apply a gripping force to the cam block 163 and instead merely rotates with the inner agitator shell 126 by virtue of the lower end 186 thereof which extends through the aperture 187. As the drive shaft 119 reaches the limiting end position and begins to rotate in a clockwise direction, the load-resisting force to which the outer agitator shell 127 is subjected is substantially reduced, the consequence of which is to tend to cause the inner and outer agitator shell 126 and 127 to rotate relative to the cam block 163, thereby moving the outer agitator shell 127 axially downwardly to a low level agitation position thereof. Immediately upon clockwise rotation of the drive shaft 119, however, the spring clutch 182 immediately frictionally grips the cam block 163 and rotates therewith, thereby causing the inner agitator shell 126, and hence the outer agitator shell 127, to rotate in a clockwise direction jointly with the drive shaft 119, thus precluding relative rotation between the cam block 163 and the outer shell 127 and further precluding an axially downward movement of the outer agitator shell 127.

FIGURE 6 illustrates the relative positions of the spring clutch 182, the cam block 163 and the inner agitator shell 126 when the drive shaft 119 is at rest. FIGURE 7 illustrates the relative positions of these parts after the drive shaft 119 and the cam block 163 have been rotated in a counter-clockwise direction but before the biasing force of the spring 190 has overcome the load-resisting force being applied to the outer agitator shell 127 by the Wash load.

FIGURE 8 illustrates the relative positions of the parts after the direction of rotation of the drive shaft 119 in the cam block 163 has been reversed and the spring clutch 182 has frictionally gripped the cylindrical wall 181 of the cam block 163 to rotate jointly therewith in a clockwise direction. Rotation of the spring clutch 182 has caused joint rotation of the inner agitator shell 126 and thus when the drive shaft 119 is rotated in a clockwise direction of rotation the cam block 163 as well as the inner and outer agitator shells 126 and 127 rotate jointly with the drive shaft 119.

At the end of the wash cycle it is possible that the drive shaft 119 may come to rest while it is rotating in a clockwise direction. If this occurs the spring clutch 182 may maintain a tight grip on the cam block 163, thus precluding the outer agitator shell 127 from moving axially downwardly to the low level agitation position thereof. For this reason the underside of cap 188 is provided with a tab 196 as shown in FIGURE 8 which, upon rotation of the cap 188 in a counterclockwise direction, engages the upper end 183 of the spring clutch 182 to release the tension in the clutch, thus enabling the spring clutch 182 as well as the inner and outer agitator shells 126 and 127 to rotate relative to the cam block 163. The helical spring 190 thereupon urges the outer agitator shell 127 axially downwardly so that the agitation vanes 124 again assume a low level agitation position as shown in the solid lines in FIGURE 5. This is desirable so that the inner and outer agitator shells 126 and 127 will be returned to their relatively neutral position at the end of each wash cycle, so that at the commencement of the subsequent wash cycle the angle of displacement to which the inner and outer agitator shells 126 and 127 are moved will correspond to the size of the subsequent load of laundry material, and not to the size of the preceding load.

Although minor modifications might be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably come within the scope of our contribution to the art.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The method of automatically adjusting the agitation level of a washing machine having an agitator shell and an adjustable agitation vane mounted thereon comprising the steps of transmitting a driving torque to the agitator shell, subjecting the agitator shell and agitation vane to a turn-resisting force imposed by the washing load in the machine, increasing the driving torque to a level exceeding the turn-resisting force to rotate the agitator shell, and

adjusting the agitation vane in relation to the level of the driving torque required to exceed the loadimposed turn-resisting force.

2. In a washing machine having an agitator assembly including a rotatable agitator shell and an adjustable agitation vane coupled to the agitator shell for rotation therewith to vary the agitation level of the washing machine, the improvement comprising,

means for providing an agitator assembly driving torque in excess of the load-imposed turn-resisting force to which the agitator assembly is subjected by virtue of the washing load in the machine to rotatably oscillate the agitator shell, and

means operatively interconnecting said agitator assem- ,bly and said torque-providing means and responsive to the magnitude of the driving torque being applied to the agitator shell for adjusting the agitation vane as a function thereof.

3. The washing machine as defined in claim 2 wherein said agitation vane is adjustable between first and second positions to increase the level of agitation produced thereby and wherein said torque-responsive means causes said agitation vane to move from said first toward said second position as the driving torque increases in order to increase the agitation level of the machine as the washing load increases.

4. The washing machine as defined in claim 2 wherein said interconnecting means comprises a lost-motion coupling between said torque providing means and said agitator shell.

5. The washing machine as defined in claim 3 wherein said torque-providing means comprises a drive shaft and including,

means mounting said agitator shell for movement between first and second positions relative to said drive shaft, and means interconnecting said agitator shell and said agitation vane for simultaneous movement thereof between their respective first and second positions,

said torque responsive means providing for movement of said agitator shell from said first to said second position thereof upon an increase in the torque being applied to said agitator shell.

6. A washing machine comprising,

a rotatable drive assembly,

a rotatable agitator assembly, and

drive coupling means interconnecting said drive assembly and said agitator assembly and allowing relative displacement therebetween which varies in magnitude as a function of the magnitude of the turnresisting forces to which the agitator assembly is subjecting by virtue of the washing load in the machine,

said agitator assembly including means for varying the agitation level thereof as a function of the magnitude of the displacement between the agitator assembly and the driving assembly.

7. The washing machine as defined in claim 6 wherein said drive coupling means comprises a resilient member for providing a lost-motion connection between said drive assembly and said agitator assembly.

8. The washing machine as defined in claim 6 wherein said agitation level varying means comprises an agitation vane moveable between first and second positions relative to said drive assembly to vary the agitation level of the washing machine.

9. A washing machine comprising,

a rotatable drive shaft,

a rotatable agitator assembly for agitating and laundering a Washing load in the machine,

means mounting said agitator assembly for rotation relative to said drive shaft,

said agitator assembly including means for irrcreasing the agitation level of the washing machine as a function of the relative rotational displacement between said drive shaft and said agitator assembly, and

drive coupling means including a resilient member interconnecting said drive shaft and said agitator assembly for rotating said agitator assembly and for allowing rotational displacement between said drive shaft and said agitator assembly which varies as a function of the rotational resistance imposed on the agitator assembly by the washing load.

10. The washing machine as defined in claim 9 wherein said driving coupling means comprises a helical spring.

11. The washing machine as defined in claim 9 wherein said agitation level increasing means comprises an agitation vane movable radially with respect to said drive shaft andmeans for moving said agitation vane in response to relative rotational displacement between said drive shaft and said agitator assembly.

12. The washing machine as defined in claim 9 wherein said mounting means comprises means for mounting said agitator assembly for axial movement relative to said drive shaft and wherein said drive coupling means comprises cooperating helical groove and pin means mounted on said agitator assembly and on said drive shaft for providing relative axial displacement therebetween in response to said rotational displacement.

13. The washing machine as defined in claim 12 wherein said agitation level increasing means comprises an agitation vane assembly extendible in an axial direction in response to axial movement of said agitator assembly.

14. The washing machine as defined in claim 12 including means for rotatably oscillating said drive shaft and wherein said drive coupling means further comprises oneway clutch means between said drive shaft and said agitator assembly whereby said resilient member drives said agitator assembly in one direction of rotation and said one-way clutch means drives said agitator assembly in an opposite direction of rotation.

15. A Washing machine comprising,

drive means including a rotatable oscillating drive shaft, an inner agitator shell mounted on said drive shaft for relative rotation therewith,

10 an outer agitator shell surrounding said inner agitator shell,

said drive shaft and said innerand outer agitator she ls being axially aligned with one another, cam means including a helical cam surface formed on said drive means,

means forming a vertical slot in said inner agitor shell,

means including a pin mounted fast to said outer agitator shell and extending through said vertical slot and into cam follower relation with said cam surface for providing joint rotation of said inner and outer agitor shel s and relative axial movement there-between and for providing axial movement of said outer agitator shell between first and second positions in response to relative rotation between said outer agitator shell and said drive shaft,

means biasing said outer agitator shell axially toward said first position, and

agitation vane means on said outer agitator shell movable axially to increase the effective action surface thereof upon movement of said outer agitator shell to said second position in response to relative rotation between said outer agitator shell and said drive shaft caused by a washing load drag on said outer agitator shell.

16. The washing machine as defined in claim 15 where 4 in said biasing means comprises a helical spring bottoming at one end of said agitator shell.

17. The washing machine as defined in claim 15 and including a one-way spring clutch interconnecting said drive means and said inner agitator shell for positively driving said inner and outer shells in one direction of rotation.

18. The washing machine as defined in claim 17 and including a cap member mounted on said drive means for relative rotation and including tab means engageable with one end of said spring clutch for releasing said spring clutch in response to rotation of said cap member.

References Cited UNITED STATES PATENTS 1,796,528 3/1931 Lyons 68134 3,213,651 10/1965 Worst 68-133 3,307,383 3/1967 Cobb et al. 68-134 3,388,570 6/1968 Cobb et a1. 68-134 3,399,552 9/1968 Salisbury et a1. 68134 3,401,540 9/1968 P att et a1. 68134 WILLIAM I. PRICE, Primary Examiner 

